This invention relates generally to heaters for use in household environments. More specifically, the present invention relates to an elongate heater in which pressurized exhaust air passes through the heater element.
Conventional forced hot air heaters for consumer use are well-known and are comprised of an electrical heating element and a fan within a housing. An example of such a conventional heater 600 is shown in FIG. 6. As shown in FIG. 6, air created by axial fan assembly 602 diffuses as it approaches heater element 604. As such, this diffuse air pattern does not flow through all of heater element 604, or flows through heater element 604 at different velocities over the length of heater element 604, thereby resulting in less that satisfactory heating levels felt by the user. This problem is exacerbated if the length of the heater element is increased.
In another conventional elongated heater 700, a portion of which is shown in FIG. 7, transverse air circulator 702 has an elongated blade assembly 704. A drawback of this type of air circulator is that blade assembly 704 of has several sections 706 which must be coupled together by glue or ultrasonic welding. This assembly must then balanced to insure correct operation as well as requires the use of vibration dampers 708, 710. This adds significant expense to the manufacturing process, which translates into a higher retail price to consumers. In addition, the blade assembly in transverse air circulators is long and tends to become misaligned at top bearing 712, thereby requiring a special bearing mounted in a rubber pad to compensate for the misalignment.
There is a need for a forced air electric heater that provides increased comfort levels, provides exhaust air having a more uniform velocity across the surface of the heating element, and is more efficient and inexpensive to manufacture.
There is also a need for a heater construction having a blower assembly with unitary construction which is easily mounted in the heater unit and less expensive to manufacture.
In view of the shortcomings of the prior art, the present invention is a apparatus and method for providing thermal energy. The apparatus comprises a housing defining a first interior space and a second interior space; at least one electric heating element positioned within the first interior space; and an air circulator positioned within the second interior space and adjacent the first interior space, the air circulator having at least one intake port receiving intake air from a first flow path and generating exhaust air along a second flow path, the second flow path substantially orthogonal to the first flow path such that the exhaust air flows through the at least one heating element.
According to another aspect of the invention, the air circulator has a predetermined blade diameter and the at least one heating element has a predetermined length, and a ratio of the at least one heating element length to the air circulator blade diameter is at least 1.75:1.
According to a further aspect of the invention, the air circulator has at least one fan blade having a plurality of blade elements facing in a rotational direction of the air circulator.
According to still another aspect of the invention, the apparatus comprises a housing defining a first interior space; at least one electric heating element positioned within the first interior space, the at least one electric heating element having a length of at least 7 inches; an air circulator positioned within the housing and in fluid communication with the first interior space, the air circulator generating exhaust air for charging the first interior space with a static pressure; the air circulator having a predetermined blade diameter and the at least one heating element having a predetermined length, a ratio of the heating element length to the air circulator blade diameter being at least 2:1.
According to yet a further aspect of the present invention, a restricting means is provided for restricting a flow of the exhaust air through the heating element, such that the exhaust air from the air circulator flows through the heating element at a substantially uniform velocity.
According to yet another aspect of the present invention, the first interior space forms a plenum area between the heating element and the air circulator.
According to still another aspect of the present invention, the restricting means adjacent to at least one of the input side and the output side of the heating element.
According to a further aspect of the present invention, the restricting means is incorporated within the heating element.
According to yet a further aspect of the present invention, the velocity of the air emanating from the heating element is greater than 375 fpm at 1 foot from at least a portion of the at least one heating element.
According to yet another aspect of the present invention, the air circulator has a predetermined blade diameter and the at least one heating element has a predetermined length, and a ratio of the heating element length to the air circulator blade diameter is at least 2:1.
According to still another aspect of the invention, the restricting means has a flow through area of between 20% and 80%.
According to yet another aspect of the invention, the restricting means converts the static pressure associated with the exhaust air into an air velocity which is in turn imparted into the exhaust air and flows through the at least one heating element.
According to yet a further aspect of the invention, the air circulator is a non-transverse blower.
According to still a further aspect of the invention, the aspect ratio of the heating element is greater than 4:1.
According to yet another aspect of the invention, the aspect ratio of the heating element is about 18:1.
The method comprises the steps of providing a housing having a first interior space and a second interior space; receiving intake air along a first flow path; generating an exhaust airflow within the first interior space along a second flow path based on the intake air, the second flow path substantially orthogonal to the first flow path; generating thermal energy within the first interior space using a thermal energy generator; imparting the thermal energy into the exhaust air by passing the exhaust air though the thermal energy generator to form heated exhaust air; and expelling the heated exhaust air from the first interior space.